Will Working Out At Night Really Wreck Your Sleep?

The claim: If you've ever been told to avoid exercise in the hours leading up to bedtime, don't settle into the couch and fire up your Netflix just yet. A new study in Sleep Medicine challenges this common sleep recommendation by finding that evening workouts have no negative effects on the quality of your sleep.

The research: One thousand adults completed the 2013 National Sleep Foundation Sleep in America Poll, which included questions about how long and how well participants thought they slept each night. They were also asked to share their daily exercise habits and what time of day they worked out. People who completed tough workouts in the morning reported the best sleep quality and were 88% more likely to say they got a good night's rest than non-exercisers. But researchers were surprised to find that moderate to vigorous evening exercise seemed to have no negative impact on sleep, even for those who normally sleep poorly.

What it means: Even though typical sleep recommendations suggest not exercising during the four hours leading up to bedtime—the thinking being that working out may lead to more alertness and throw your sleep cycle out of whack—the evidence to support this is not strong, says Matthew Buman, PhD, lead author of the study from Arizona State University in Phoenix. "Exercise does have some stimulant effects that mimic caffeine, however, these effects don't appear to disrupt sleep in the same way that caffeine does."

The bottom line: It's still possible that you could experience disturbed sleep after evening exercise, especially if you already have trouble getting shut-eye. But exercise generally improves sleep and you should try to fit it into your day in any way possible. "The key is to find an exercise routine that you enjoy and can be consistent with," Dr. Buman says. If your sleep gets worse after late-night activities, then try to find a different time slot for your workouts.